<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>

     function  jisun(num1,num2,callback){
          return callback(num1,num2);
     }


    var result=  jisun(1,2,function (num1,num2){
         return num1+num2;
     })

     var result=  jisun(1,2,function (num1,num2){
         return num1-num2;
     })



     alert(result);


</script>
</html>